Electrically-operated semaphore-signal



c. s BUSHNELL. ELECTRICALLY OPERATED SEMAPHORE SIGNAL.

APPLICATION FILED SEPT. I. l92u.

Patented May 10,1921.

VENTR BY WTZRNEY ply of current to the hold-clear device, due

UNITED STATES PATENT OFFICE,

CHARLES S. BUSHNELL, or RocHEsTER; NEW. YORK, AsSIGNoR T0 GENERALRAILQWAY SiGNAL'GOMIPANY, or noonnsrnnfnnw YoRK, A coRroRArioN or NEW YORK.

Application filed September 1, 1920 SerialNo. 407,301, I

new and useful Improvements in Electrically-Operated Semaphore-Signals,of which the following is a specification.

This invention relates to electrically operated semaphore signals usedinrailway signal systems.

Semaphore signal operating mechanisms in common use, while differing toa" certain] extent in detailsof construction, generally include someform of a hold ng or retaining mechanism, herein conveniently-termed ahold-clear device, for holdingthe semaphore blade in its oneor moreoperated positions, corresponding to caution or proceed. Since thishold-clear device is energized the greater part of the time, itsefficiency is an important part of the total efiif ciency or economy ofthe .system, .The hold-clear devices commonlyused, and with which I amfamiliar, are of the type com; prising a latch or detent operated by anelectroma et. It is a well known characteristic of this type'ofhold-clear devicethat the energy required to place the device in itsoperated position, or pick it up, is somewhat greater than that requiredto retain the device in its operated condition, or hold it up. Thischaracteristic is due to the well known fact that the current in anelectromagnet required to attract its armature, is greater than thecurrent needed to hold the armature in its attracted position. In orderto make the current through the hold-clear device at different timescorrespond more nearly to that required, ithasbeen proposed to'provide ahold-clear magnet with a low resistance winding and a high resistancewinding, and use the low resistance winding for picking up the device,and the two windings in series for holding the device in its operatedposition. This change in circuit connections is made by automaticdevices, which are preferably so constructed that the change is not madeuntilthe arma ture of the hold-clear magnet has fully attained itsattracted position,.and also without interrupting the current throughthe windings of said magnet, Inaddition'to these requisites, theresometimes occurs in practice temporary interruptionsinthe Sup-Specification of Letters Patent.

ELECTRICALLY-OPERATED SEMAPHORE-SIGNAL,

Patented. May 10, 1921,

for example, to the vibration of co-ntacts of i if relays or switchboxes by passing trains. Such lnterruptlons of current ma y cause thehold-clear magnet to drop its armature, and

since it cannotpick up until its pickup circuit is establishethit isdesirable to make a change-from the holding circuit back to the pickupcircuit quickly, and particularly before the semaphore has hadopportunity to drop back to any great extent, otherwise there isfalse.and-objectionablemovement ofphe semaphore to its caution or Stopposi- 1on. a

, In certain applications of semaphore signal operating mechanisms, itis desirable to use "the, hold-clear device to perform the functions ofarelay. For example, the circuit for controlling one operated position ofthe semaphore, usually the [caution position, may be of considerablelength and include a numberof switch box orlever contacts, so

that this circuit cannot be usedto advan-,

tage for an operating circuit of the motor,

1 but must be relayed. It is'the primary pur pose of the presentinvention to meet the foregoingconditions and requisites and one of theprincipal objects of my invention is to devise an organization andarrangement of parts and circuits capable of, satisfying theserequirements in a simple and eflicie'nt manner, together with otherconditions found in the practical operation of railway signalsystems.Other specific objects and advantages of the invention will appearsemaphore signal operating mechanismembodying my invention, the parts:of said mechanism being spreadapart andlshown more with aview of makingit easy to understand the construction and operation, than with the ideaof showing the construction and arrangement preferably employed inpractice; and

Fig. 2 is a wiring diagram showing one applicationof my lmprovedsemaphore signal operating mechanism. 1

Referring t invention applied to a sema hore signal operatingmechanismof well own construction, comprising a semaphore shaft 1, towhich the semaphore blade G is fastened, t i blade bei g arrang d n thes al way Fig. 1, I have illustrated my I it I The operating motor M' isshown in a sim I 7 so that it tends to move by its own weight" I fromthe vertical position shown (convenie'ntly termed the 90 position) to a'llOII- zontal position against a suitable stop (shown diagrammaticallyat 2), this horizontal position being conveniently termedthefOFpositiOn. 5 The shaft lis connected by-reduction gearing 3 totmotor shaft l.

plified manner, and comprises the usualfield 5 and aniarmature 6.securedto .the shaft 4:.

The hold-clear device comprisesa toothed. wheel 7, which is. preferablyconnected to theshaftl'by a combinedfriction and ball clutch device, sothat said -to othedfwheel may turn freelywithzrespect to the shaft 5i inone direction, butis held against turning, except for the slipping ofthefriction clutchfin the other direction, these directions. of movementcorresponding respectively with the movement of the semaphore toward its90 or operated position, andtofward itshoriz ontal or;0.position;Coeperating withthe toothed wheel 7 is a detent or latchfmechanism,compr sing two plates 8 .pivotallypsutiported at, their upper ends on asuitably fixed member 9 (which inprac tice forms a part offtliemechanism case).

V 7 A pawl 10 is guided between said plates. by

pins .Qll and is 1 's'pring'pr'essed inward to- Ward the toothed WhieelTby a springj12. The plates Shave-a pin and slot connection attheir-1ower ends to the short arm of an angle lever 13,pivotallysupported on fixed 9 members 14.; To thelongarm of the lever 13is -conneetedthe armature 15 of the holdcleanmagnetile. This magnetisfastened p to a memberl'? forming part of the mecha- 1 nism casing, andlsprovlded with low resistjance coils or windings L and high regsistance coils-or windigs stop )in 18'seeured to the lever 13. isarranged to en gage a suitably-fixed member 19, so as to limit-thedownwardmovement ofsaid angle anglelever- 13; and insulated therefrom isa bracket 20 which has a pin-and slotconnec;

"to a blocl; 22 of insulatingmaterial'suit ably fastened to aportionofthe mechanism leverr Attached to thelong arm of the tion to theswitch member 21.1 This switch memberThas-the general shapeof across,

and is pivotally supported at; its upper end case Contacts 23 and 24-,shown conven- "tionally as varrows, are suitably supported coeperatewith the arms ofthe switch member'21.*' The operation of the holdclear.mechanismlis as follows. .*The Iparts-Jare shownin a picked uporoperated position,

pawl 1 O being in engagement with one of the teeth .ofthe toothed. wheelso as to pre-' vent rotation of :the motor shaft .4 (in thecounterclockwise direction) and-thereby hold the semaphore blade C initslverticalposi ti'on, At this: time the "'high and low' es re 99 1s ttherhblii e i *16 are connectediin series, in a. manner more fullyexplained hereinafter: When the hold-clear magnet 16 is. 'deenergized,"the angle lever 13'and armature 15 drop, due to their-own weight, andthis withdraws the pawl 10 from engagement with toothed Ywl1eel7,thereby permitting the semaphore blade tomovetoward its biased position;

At the 'same'tim'e'the switch member 21- is shifted out of engagementwith contact'. 24

into engagement with contact 23, for. the

purposes hereinafter explained. When the hold-clear magnet 16 is againenergized, its a 'fastenedby screws to a shaft 26, which is connected bysegmental gears 27, 28 to the semaphore shaft 1. Associated with thedrum '25 area number of contact groups, eachof these groups consistingof a pair ofcontact springs 29, and a contact strip, or strips 30 on thedrum 25. The contact springs 29 are carried by bars 31 ofsuitableinsulatlng material, which in turn are fastenedfto the framework of thecircuit con troller. By

, making; the contact strips on the dr'umof the appropriate lengthandposition, the various pairs of contact springs 29'maybe connectedelectrically in any de sired position of thedrum 25 and throughout anydesired range of its movement.

Also associated with the. drum 25 is a de: 3 I 'vlce, convenientlytermed a slip contact S.- In

the particular construction illustrated, this slip contact comprises ashoe-like slip mem} ber 32 riding in a "shallow groove around the drum25; This slip member, 32 is pressed 'against' .the -drumfl 25 by aspring 33,. the connection between .said member and said 7 springlbeing.preferably made pin fit-' ting loosely in sockets therein,.softhatthemember' 32 may travel with the-drum25 to a limited jextent'ineitlierdirection] A V v 'contactspring 341s arranged to be engaged by .theslip-'inember32, when'said member is carried in Lone] direction; Thefriction ;between the slip member 32ai1d the drurn25' V is sufficienttocause movement of said slip member into and out of engagement' withthe contact spring-34, The circuit connections controlled by the slipcontact Stare between the springs 33%34;

ln order'toexplain the various features of the construction andoperation of my 1mproved..semaphore slgnal operating mechanis'm', Ihaveillustr'ated in Fig. 2 one prac tical application of this mechanism."Refer-f e s Bis-. 5? isill si ed n a The other circuits are open.

ventional manner two track sections or blocks A and- B, with trackrelays 35, signals 36 and 3'1 at the entrance to said blocks, andtheparts and circuits associated with the signal 36. Thecontactgroups ofthe circuit controller are shown according to established convention at38 and 39, as switch arms moving with the semaphore blade" 36 and makingcontact withcurved segments through thefangles of movement of said bladeindicated. For example, circuit contro1ler-38 makes contact from Oto47.D designates a line relay of the usual construction controlled by acircuit controller 40 operated by the signal 37, said circuit controllerbeing closed so as to energize the relay D, when the semaphore 37 is inthe or caution positionfo r the 9O or proce'ed position, or any positionin between. K designates a switch box contact, or the contact of alever,;or'the like. The other parts shown in Fig.2" correspond to thoseillustrated in Fig. lalready described, the samereferencecharactersbeing employed; 1

OperationzThe parts and circuits are shown in Figs. 1 and 2correspondingto the proceed positionof thesemaphorel At this time the'hold-clearmagnet 16 is energized with its coils H and L in series, bya circuitwhich may be tracedas follows: commencing at battery 41, wire 42,contactK, wire 43, front contact 44 of track relay 35, wires 45 and'46,front contact 47 of relay D, wires 48 and49, coilsL, wires 50 and 51,coils H and wires 52'and 53" back to the battery.

When a trainenters the block Aand drops track relay 35, it opens theholdingcircuit of the hold-clear magnet' 16, and allows its armature15't0drop. This releases the semaphore blade and allows it to gravitatetoward its stop position. At the same time the switch member 21 isshifted, thereby establishing a snubbingcircuit through the motor M,said circuit comprising wire 54, switch member 21, contact23,wire 55',snubbing resistance -56,wire 57, andthrough the armature 6 and field 5offmotor M; The motor M having a low resistance shunt around itsarmatureand field acts as a generator, thereby retarding the movement ofthe semaphore blade andassociated gearing, so that it stops in thehorizontal position without severe shock and jar. During the movement ofthe semaphore blade toward its biased position the circnit controllerdrum 25 is turned in the direction (counterclockwise as shown in Fig. 1)tomove the slip member 32 into engagementwith spring 34, so as toestablish an electrical connection between'springs 33 and34. Thisclosesa low resistance shuntforthe coils H of the hold-clear magnet 16comprising wires 51, 58, slip contact and wires 59 and 52. f

When thetrain leaves the block A and armature 15 of the hold-cleardevice, thereby shifting the switch member 21 back to theposition shownand establishing an opcrating, circuitforthe motor as follows;COIHIIIGIlCIDg at battery 60, wlre 61, circuit controller 39, (nowclosed), wire 62, contact 24, switch member 21, wire 54, field 5 andarmature 60f the operating motor M and wire 63 back to the batteryThe'motor drives the. semaphore from its horizontal or 0 position towardits vertical position.' When the armature 15. picks up,the pawl 10 isprojected into engagementwith the toothed wheel 7 but on account of theball a clutch connectionbetween the wheel 7 and the shaft 4, saidshaftmay rotatefreely while thewheel :7 is held stationary. After affewdeg-recs movement of the semaphore shaft 1, from 2 to;5 degrees, thecircuit con troller drum 25 carries with it the slip memoer '32 outofengagement with'the spring 34, thereby interrupting the shunt around thehigh resistance coils H, and placing these coils in series withrthecoils L. The armature 15 being attracted at this time, the smallercurrent flowing through the coils H and L in seriesis sufficient to holdup this armature. When the semaphore blade attains about 43, that is,about'2- below its 45 or caution position, the circuit controller 39opens and interrupts the operating circuitfor the motor M. The semaphorebladeand associatedgearing, however, usually-'moveia littlefarther byvirtue of the acquired momentum, so that finallyit is brought. to restat its 45 orcaution position' and is held there by the pawl 10. co-

ated to the caution. position, closes its cira, I

cuit controller 40, and energizes relay D.-

Current is now supplied to the operating motor M from battery 60 alongwires 61 and64, front contact 65 of relay D, wire 66, circuit controller39 (closed fromabout 40 to 88), wire 62,*contact 24, switch mem-.

. ber 21,'wire';54,'field5 and armature 6 of motor M a d'vf e 6 c o heba te y- Current is maintained on the hold-clear magnet 16 through wires46 and 48 and front contact 47' of: relay D; and the signal.

is-operated to its 90 or vertical position 1 and held there.

In addition to the movements already described, occasionallythesemaphore is moved from the;90. position to the 45 position, .asforexample when a train backs into, the

block B from the block ahead. During this movement 'of the semaphore,the hold-clear magnet 16 drops as before, and closes thesnubbingicircuit' for the motor. Also -the slip contact S closes; and atabout 47 9 the hold-clear magnet 16 picks up again through circuitcontroller 38. The semaphore blade and its associated gearing, however,acquires considerable momentum during its downward movement and cannotbe instantly brought to a stop. Consequently,

'when the pawl 10 is? thrown into engagement with the toothed wheel 7 atabout 47".,

the friction clutch. between said wheel and v the shaft 4 slips and theblade drops ,still fartherna few degrees below the 45 posi-' tion. Whenthe semaphore drops below 43 7 the motor operating circuit-isestablished at circuit controller 39, thereby starting to the lowresistance pickup circuit to the high resistance holding circuit of thehold-clear drive the semaphore upward again. During this upward movementthe slip contact opens and throws the coils H and L in series.

At about 43 the motor operating circuit'is 7 broken, and after a littlemore upward movement, thesemaphore settles back and is held in its 45.position by the hold-clear device.

It sometimes happens in practice that a circuit: controlling signal ismomentarily interrupted. 'For example, a switch box- *40' contact,as K,maybe poorly adjusted and perhaps the contact surfacesare dirty, so

that the jar and vibration of a passing train opens the circuittemporarily. iThis, of

course, deenergizes the hold clear magnet 16"; but in accordance withthe present invention, this magnet may pick up again. as

soon asthe-semaphore blade moves back a few degrees,-since the slipcontact is closed by such movement and puts the low: resist ance coilLalone in the circuit.

It will" be observed that the change-from device is made by the movementof the semaphore circuit controller, andsince' this movement; cannotoccur-unt1l after the 7 switch member 21 has shifted, it is assuredthatthe armature offthe holdclear device is fully attracted before'thischangeis made. In other words, a change from the pickup to the holdupcircuit is made by parts set into operation by the attraction of thearma V ture of the hold-clear device but sufliciently slow" acting oassure-that said" arm ture hasattained its fully attracted position,regardless of any delicate or precise adjustment of contacts. Anotherimportant feature of the invention is the ability of. the semaphoreoperating mechanism to pick up at any-part i of its movement, so thattemporaryinterruptions of current do lnotsend the semaphore all of theway back to; its 0 position before itcan return to its operatedposition.

The particular construction and arrange -ment of parts and circuitsillustrated may be modified and adapted to suit, varying requirementswithout departing from the invention. 7

What I claim p by Letters Patent of the United States is '1. In asemaphore signalfloperating mechanism, the combinationf with ahold-clear device having a pickup circuit andaholding circuit, of meansoperated in accordance withthedirection. of movement of the semaphore-f0r-.controlling said circuits.

2. In a semaphore signal operating mechani'sm, the combination :with ahold-clear device having a pickup circuit and a holding circuit,ofgnieans responsiveto. the dias new and desire to secure rectionof'movement'of the semaphore for causing alternat closing ofsaidcircuits as the semaphore moves a few degrees in opposite directions- 1r 3.111 a semaphore signal operating mechanism, ,the combination with aholdrclear device having apickup circuit and a holding:

circuit, of 'slow acting means responding to the energization of saiddevice for changing means operated in accordance with the di rection ofmovement of the semaphore for out 'interrupting'thefiow of current.

establishing said circuits in succession with Ina semaphore signaloperating mechanism, the-combination with a hold-clear device having apickup circuit 'and a'holding circiut, of-means for changing from the ipickup circuit to the holding circuit as the semaphore moves arfewdegrees toward its operated position and for changing from the holding,circuit to .the'pickup circuit as the semaphoremovesbackward a'few dgrees from its existing position toward its biased position. v

6.1 In a semaphore signal operating mechanism, the combination with ahold-clear" device having a low: resistance coil and a. high resistancecoil, a shunt for the high resistance, coil, and means for opening and;

arness by the hold-clear device for controlling the operating circuit,apickup circuit and a holding circuit for the hold-clear device, andmeans responsive to the direction of movement of the semaphoreforcontrolling the "circuits of said device.

8. Ina semaphore signal operating mechanism having a hold-clear deviceand an operating motor, an operating circuit for the motor, circuitcontrolling means actuated by the hold-clear device for controlling theoperating circuit, a pickup circuit and a holding circuit for thehold-clear device,

and a slip contact responding to the direc tion of movement of thesemaphore for al-i v ternately establishing the circuits of said,

device, said slip contact being shifted after a .feW degrees movement ofthe semaphore.

9. In a semaphore signal operating mechanism having an operating motorand a hold-clear device provided with high resistance and low resistancecoils, an operating circuit for the motor, means actuated by thehold-clear device-for controlling the operatingcircuit, a shunt for thehigh resistance coil, and'a slip contact for opening and closing saidshunt, said slip contact being shifted by a few degrees movement of thesemaphore in opposite directions. a

In testimony whereof I have aflixed my signature.

CHARLES S. BUSHNELL.

